Hydrazine hydrate (1:1) → 4-(3-bromobenzyl)-5,7-dimethyl-2,6-dihydro-1H-pyrrolo[3,4-d]pyridazin-1-one

HRID 1091733Notes

Reaction equation

HRID 1091733 reaction equation
O.[NH2:2][NH2:3].[Br:4][C:5]1[CH:6]=[C:7]([CH2:11][C:12]([C:14]2[C:15]([C:21]([O:23]C)=O)=[C:16]([CH3:20])[NH:17][C:18]=2[CH3:19])=O)[CH:8]=[CH:9][CH:10]=1>C(O)(=O)C>[Br:4][C:5]1[CH:6]=[C:7]([CH:8]=[CH:9][CH:10]=1)[CH2:11][C:12]1[C:14]2[C:15](=[C:16]([CH3:20])[NH:17][C:18]=2[CH3:19])[C:21](=[O:23])[NH:2][N:3]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 57791779Methyl 4-(2-(3-bromophenyl)acetyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate

Product 1

HCID 1361018774-(3-bromobenzyl)-5,7-dimethyl-2,6-dihydro-1H-pyrrolo[3,4-d]pyridazin-1-oneYield 56.8%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Hydrazine hydrate (0.110 mL, 1.48 mmol) was added to methyl 4-(2-(3-bromophenyl)acetyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate (49) (0.470 g, 1.34 mmol) in acetic acid (20 mL). The resulting solution was stirred at room temperature for 2 days. The reaction mixture was evaporated to dryness and redissolved in EtOAc (200 mL), and washed sequentially with 2M NaOH (100 mL) and saturated brine (50 mL). The organic layer was dried over Na2SO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 100% ethyl acetate in isohexane. Pure fractions were evaporated to dryness to afford the desired material as a beige solid (0.253 g, 56.7% yield); 1H NMR (400.132 MHz, MeOD) δ 2.18 (3H, s), 2.50 (3H, s), 4.03 (2H, s), 7.04-7.11 (2H, m), 7.25 (2H, m); m/z (LC-MS, ESI+), RT=1.84 min (M+H=333.97).

Workup

  1. customThe reaction mixture was evaporated to dryness
  2. dissolutionredissolved in EtOAc (200 mL)
  3. washwashed sequentially with 2M NaOH (100 mL) and saturated brine (50 mL)
  4. dry with materialThe organic layer was dried over Na2SO4
  5. filtrationfiltered
  6. customevaporated
  7. customto afford crude product
  8. customThe crude product was purified by flash silica chromatography, elution gradient 0 to 100% ethyl acetate in isohexane
  9. customPure fractions were evaporated to dryness

Sources & evidence

ORD record
ord-55ae696c119642d39af1e0d670be42db
Source dataset
uspto-grants-2012_03
Patent number
US08129380B2

Reaction notes

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